Sci: Lutjanus argentimaculatus

Common Names: The mangrove jack or jack is also called red bream or red chopper in some areas and, less commonly, dog bream or red perch. Mangrove jack are occasionally confused with two similar or closely related fish; the sometimes poisonous red bass (L. bohar) and the fingermark bream (L.johnii).

Description: This deep-bodied, medium-sized member of the family Lutjanidae is characterised by large, dark eyes, powerful jaws and strong, canine teeth. The base colour of the mangrove jack varies from olive-green through grey to a rusty, ochre or brick red. This is usually overlaid with lighter or darker vertical stripes, but these are not always evident. Another common colour variation features a darker centre on each scale, giving a spotted or chequered effect. Juvenile jacks are particularly striking. Their vertical bands are pronounced and they have fine, electric-blue lines around their eyes and a flush or crimson and yellow in their white-tipped ventral fins.

Size: Most jacks caught on hook and line weigh from 0.4 to 2 kg, although 2.5 to 4 kg fish are reasonably abundant in more remote areas. Exceptional fish weighing up to 12 kg and more mainly come from offshore reefs.

Distribution: Although more common in tropical waters, mangrove jacks are found from about Sydney Harbour in the south, right around the northern half of the country to Shark Bay in Western Australia. They range from freshwater rainforest streams, down through the tidal reaches of coastal rivers, bays and harbours and out to adjacent headlands and reefs. Large adult jacks may move several kilometres offshore to take up residence on deeper reefs or wrecks.

Fishing Techniques: The mangrove jack is one of the most popular and sought-after tropical estuarine species. Many are taken on live or dead baits fished close to cover, or on lures - especially minnow-style plugs or wobblers - cast, retrieved or trolled from a boat, or from the river bank. Jacks are powerful, no-holds-barred battlers that will dive back into the snags and cut a line if given the slightest chance to do so. Their strike is sudden and hard, often taking the angler by surprise.

Eating Qualities: The mangrove jack is a delicious, sweet-fleshed fish, although very large specimens tend to be somewhat dry and coarse. If there is any doubt about distinguishing mangrove jacks from red bass (such as with large, reef-caught fish) the fish should not be consumed, as the red bass is a regular carrier of the toxin ciguatera, which can cause illness and even death.

By Steve Starling